This invention relates to an aqueous organosiloxane liquid composition compounded with an aqueous modified organosilicon compound, and uses thereof. More particularly, it relates to an aqueous organosiloxane liquid composition compounded with an aqueous modified organosilicon compound, which can form, when exposed to the atmosphere of up to 300.degree. C., a siloxane polymer composition having polysiloxane bonds as a main chain and being used for forming a film, fibers, a coating material (e.g. paint), a binder, a composite structure, a composite sheet or a building material and uses of the composition.
The curing reaction mechanism of polymerization of organosiloxane to form a siloxane cured product is considered a condensation reaction or addition reaction of reactive siloxane in the presence of water. With the organosiloxane of the present invention, too, functional alkoxy groups react with water to cause a dealcoholation reaction and produce silanol groups (first step). Then, the silanol groups in turn react with the alkoxy groups of a cross-linking agent to undergo a condensation reaction (e.g., dealcoholation, deoximation, removal of acetic acid, etc.), resulting in polymerization and formation of a polymeric siloxane cured product having a three-dimensional network structure (second step).
On the other hand, organosiloxane compounds, particularly silicone oils, show such high water-repellent properties that they fundamentally repel water.
In general, varnishes, coating compositions, adhesives, fibers, and the like are mainly based on organic resins and secondarily organic solvents. Recent living environmental regulations have required incombustible or fire retardant, pollution-free materials in increasing fields. Under such situations, conventional coating compositions involve many problems since they contain an organic solvent which is dangerous and can cause environmental pollution and contain as a major component an organic resin which is susceptible to sunlight and has less weatherability in comparison with inorganic materials and is susceptible to heat or fire and highly flammable. Hence, pollution-free, Earth-friendly substitute materials involving no such problems and being used for a coating composition have eagerly been desired in many fields.
In order to meet the requirement, siloxane compounds which have --Si--O-- bonds resistant against heat or light and against chemical oxidation and which have good weatherability and high heat resistance have widely been investigated, part of the investigation results having been put into practice. Typical examples of the results and remaining problems are described hereinafter mainly referring to coating compositions and coating materials.
As a popular example of applying organosiloxanes to coating compositions, there are illustrated anti-corrosive zinc-rich coating compositions developed in World War II and capable of forming a coating film upon being dried at ordinary temperature.
There have been developed coating compositions prepared by diluting, with an organic solvent, polymers of organosiloxane or modified organosiloxane or copolymers thereof with various organic compounds, together with or without other organic resins. Most of the conventionally developed techniques are based on the above-described compositions. For example, a technique of forming a heat-resistant, anti-corrosive coating by air-drying or hot-air drying is disclosed in, for example, Japanese Examined Patent Publication No. 63-28942, and a technique of diluting an organosiloxane with an organic solvent and forming a film using the composition at an ordinary temperature or under heating is disclosed in many publications such as Japanese Examined Patent Publication No. 63-58191.
There have been many examples of merely combining organic compounds (organic resins) and organosiloxanes to prepare coating materials or the like. Most of them require heating upon film formation. Typical example thereof is described in Japanese Examined Patent Publication No. 55-41274, etc.
Many studies have been made on utilization of organosiloxane as heat-resistant coat. Japanese Examined Patent Publication No. 63-35183 discloses one typical example thereof wherein a coating composition containing a modified silicone resin as a major component is baked at 180.degree. C. to form a heat-resistant coat.
As an example of utilizing pure organosiloxane, there is illustrated a technique of preparing a durable, stainproof transparent film composed of organopolysiloxane (Japanese Unexamined Patent Publication No. 3-68676).
A technique of using a keto-enol tautomer compound for stabilizing a curing catalyst of a metal-containing organic compound in the polymer-forming organosiloxane has also been disclosed in Japanese Examined Patent Application No. 48-17859 and Japanese Unexamined Patent Application No. 1-129066.
Techniques of curing a one-pack type organosiloxane composition at an ordinary temperature are disclosed in U.S. Pat. Nos. 3,294,739, 3,647,917 and 4,111,890.
However, these patents do not disclose a technique of previously incorporating water in a homogeneous state in the liquid organosiloxane and forming a siloxane polymer composition by the action of the incorporated water, much less a technique of utilizing the water-retaining ability of an organosilicon compound having at least one polyether group for effectively incorporating water in the liquid organosiloxane.
The inventor has formerly made an invention relating to a solvent-free organosiloxane composition which, when subjected to specific conditions, can be cured at an ordinary temperature or under heating to provide a product such as a coating material and a binder, and have filed the invention as Japanese Patent Application Nos. 4-180127 and 4-36273.
Furthermore, the inventor has suscessively found that sufficient flexibility and adhesively expanding or contracting properties to the expansion or contraction of a substrate can be given to a produced siloxane polymer by controlling the content of the total metal elements in the solvent-free organosiloxane liquid composition at a level of 25% by weight to less then 40% by weight in terms of MO.sub.y/2 wherein M represents a metal) and have filed a patent application directed to this technique (Japanese Patent Application No. 5-248358
In this specification, the term "homogeneous state" means that any portion of the composition has the same formulation without forming two or more portions.
In this specification, the silicon content or concentration is in some cases presented in terms of "SiO.sub.2 % by weight" on the basis of its oxide. Similarly, the content or concentration of the total metal elements (aluminum, boron, silicon, titanium, zirconium, zinc, cobalt, etc.) is in some cases presented in terms of "MO.sub.y/2 % by weight" on the basis of their oxides.
Several words are defined as follows and will be described in detail in the specific description of the invention to be described hereinafter.
The term "siloxane polymer composition" is an abbreviated term for a cured siloxane product containing a main chain of polysiloxane bonds produced by exposing the aqueous organosiloxane liquid composition to the atmosphere of up to 300.degree. C. This term "siloxane polymer composition" is a general term for cured siloxane products constituting a shaped polymer composition, an adhesive polymer composition, a composite structure, a composite sheet and a building material to be defined hereinafter.
The term "shaped polymer composition" means a shape-retaining polymer composition which is composed of a cured product of the organosiloxane liquid composition of the present invention and is shaped in a particular form such as a film, a thin plate, a sheet, fibers, a string, a mass, a sphere, a rectangular member, etc.
The term "adhesive polymer composition means a polymer composition which forms a coating film or a binder adhering to the surface of various substrates and can be used as, for example, a coating composition, a varnish, an undercoating composition, a protective coating material having some thickness, an adhesive, a binder, a joint mixture, an agent for binding aggregates, a cementing material, and an anchor-fixing material.
The term "composite structure" means a structure wherein a cured product of the organosiloxane liquid composition of the present invention functions to unify a reinforcing material in a various shape such as a honeycomb, a massive structure, a plate, a net, fibers, a cloth, etc, aggregates, moldings, or a shaped product.
The term "composite sheet" means a sheet wherein a cured product of the organosiloxane liquid composition of the present invention unifies with a base material in a form of a sheet, net, cloth or texture.
The term "building material" means a building material wherein a cured product of the organosiloxane liquid composition of the present invention is coated on the surface of a building material base such as a metal product, a concrete product made of, for example, cement, a ceramic or clay product, a product of a natural material such as wood or bamboo, a synthetic product thereof, etc.
One of the important factors is "water". That is, "water" fundamentally repels a liquid organosiloxane compound, and they are in a so-called "water-oil" relationship with each other. Therefore, a system containing both a liquid organosiloxane compound and water fundamentally does not form a homogeneous state, but forms two separate phases. On the other hand, "water" functions to polymerize the liquid organosiloxane compound according to the moisture-curing mechanism as has been set forth hereinbefore.
The inventor has noted this antinomic relationship between "water" and the organosiloxane compound, and has searched the proper conditions under which important "water" effectively acts on the organosiloxane. As a result, the inventor has found that "water" can previously be incorporated in the organosiloxane liquid composition of the present invention in a homogeneous state under special conditions, and that the incorported water effectively functions from inside of the liquid composition to produce a useful siloxane polymer composition as a result of uniform curing.
As has been seen with the above-described prior art, the application of the organopolysiloxane as a coating component has begun with its auxiliary addition to an organic compound-based coating composition containing an organic polymer or an organic resin having a main chain of C--C bonds and being excellent in filming properties, dilution properties with a solvent and drying properties after being coated for the purpose of improving the coating composition.
Hence, these conventional coating compositions inevitably contain the dangerous, trouble-causing organic solvents, and there have been seen no positive attempts to produce and commercialize solvent-free coating compositions mainly using organosiloxane, and an incombustible or fire retardant siloxane polymer composition such as a shaped polymer composition in a form of film or fiber and an adhesive polymer composition such as a coating material or an adhesive.
The inventor has given attention to the following fundamental problems which conventional films, fibers, coating compositions, coating materials, binders, structures, sheets, building materials, etc. utilizing the above-described prior art polymers and to the fact that there have been no techniques which take into consideration protection of the environment of the earth and saving of energy and labor.
1) In the case of using an organic compound having --C--C-- bonds as the main chain:
(a) use of an organic solvent which is dangerous and harmful is inevitable; PA0 (b) the composition is quite susceptible to oxidation by heat or fire; PA0 (c) a poisonous and harmful gas is produced upon combustion; PA0 (d) the composition provides quite poor weatherability. PA0 (a) the composition provides poor flexibility; PA0 (b) the composition provides poor alkali resistance due to its high reactivity with an alkali metal element; PA0 (c) cured products formed due to hydraulic property contain many pores through which water has gone, and thus the products lack water impermeability; PA0 (d) the composition has poor adhesion properties to an organic material, and cannot be applied to a coated surface; PA0 (a) there have been no techniques of applying solvent-free organosiloxane to formation of a three dimensional polymer; PA0 (b) there have been no complete techniques of applying the material to a coating composition, etc. permitting site application; PA0 (c) there have been no popular coating compositions capable of forming an incombustible or fire-retardant, seemingly thick, beautiful, lustrous coat; and PA0 (d) this material is liable to suffer stain due to its high insulating properties. PA0 1. A water-containing or aqueous, homogeneous liquid composition can be prepared by previously dissolving water in an organosilicon compound having at least one polyether group and compounding the resulting solution with a liquid siloxane compound. In addition, the water to be used may be acidic or alkaline water. PA0 2. When the structural main chain of the fundamental skeleton consists of siloxane units [(--Si--O--).sub.n ] and the content of the total metal elements of the composition is controlled within the range of from 20% by weight to less than 65% by weight in terms of MO.sub.y/2, there can be formed a siloxane polymer composition which has sufficient heat resistance with no fragility and which exhibits good adhension to an expanding or contracting substrate. In addition, this system can be maintained in a liquid state without any solvent. PA0 3. When the above-described specific organosiloxane liquid composition is exposed to the atmosphere at a temperature of up to 300.degree. C., a uniform siloxane cured product having polysiloxane bonds as a main chain is produced in a short time to provide a shaped polymer composition, an adhesive polymer composition, a composite structure, a composite sheet, a building material, etc. PA0 4. The resulting cured product undergoes less stain, since insulation of the polymer is broken due to the presence of hydrophilic polyether groups in the product. PA0 (1) an aqueous modified organosilicon compound can be prepared by dissolving water in an organosilicon compound having at least one polyether group as a side chain or a terminal group; PA0 (2) the aqueous modified organosilicon compound containing dissolved therein water can be readily dispersed in an organosiloxane liquid composition to attain a uniform state; PA0 (3) when the aqueous modified organosilicon compound further has an alkoxy group, it can be a constituent of the polymer composition together with the organosiloxane liquid composition, the cross-linking agent, etc; PA0 (4) curing reaction of an aqueous organosiloxane liquid composition prepared under the above-described conditions is readily initiated by exposing the liquid composition to a temperature of up to 300.degree. C., and is completed in the shortest time under the particular conditions to form a polymer composition with desired properties; and PA0 (5) water to be employed may contain an acidic material to a degree of 3 to less than 7 in pH or may contain a basic material to a degree of 7 to less than 10 in pH, and such water exhibits an additional catalytic action to obtain better properties. PA0 (1) A shaped polymer composition in a form of a film, thin sheet, fibers, strand, mass, sphere, square bar or other specific form, formed without other materials. PA0 (2) An adhesive polymer composition to be applied to the surface or interior of various substrates such as a coating or varnish, a protective coating having some thickness, an adhesive, a binder, a joint mixture, amassing or unifying agent for various aggregates, a cementing material, and an anchor-fixing material. PA0 (3) A composite structure unified with a reinforcing material with a form of honeycomb, mass, plate, net, fiber or cloth or with aggregates, moldings or structural products. PA0 (4) A composite sheet unified with a sheet base with a form of film, net, cloth or texture. PA0 (5) A building material formed by applying the siloxane composition to the surface of a building material base such as a metal product (e.g., an iron-made product), a concrete product, a ceramic or clay product, an enamel product, a product of a natural material such as wood or bamboo or a synthetic product thereof.
2) In the case of using water glass having incombustible --Si--O-- bonds as the main chain:
3) In the case of using a polymer having organosiloxan as the main material: